In a skillet, saute the onion in butter.
Remove from the heat; stir in the spinach, salt and nutmeg.
In a bowl, combine the cottage cheese, cream, Parmesan cheese and eggs; mix well.
Stir in the spinach mixture.
Pour into pie shell.
Bake at 350° for 45-50 minutes or until a knife inserted near the center comes out clean.
Let stand 5 minutes before cutting.